Build plugin Browse experience

[brsbl]

Product intent and requirements

• Make Browse scalable and scannable through category shelves while keeping the existing creation hero intact.
• Use one shared search, category-filter, sort, and card system so Browse states feel like one product rather than separate layouts.
• Let users search and filter without losing shelf context; sorting may flatten results when ranking becomes the primary task.
• Keep category and install metadata compact, semantic, and subordinate to plugin identity.
• Reuse shared collection and hero primitives so later plugin surfaces do not fork the interaction model.

What was wrong

Browse presented one publisher-grouped grid, so users could not scan plugins by job, restore shelf context after sorting, or understand category consistently across shelf and flat-list states. The hero and shared collection primitives were also app-local, which prevented reuse by derivative plugin pages.

What changed

• Adds category shelves, New & Notable, category filtering, search, and recently-added/most-installed sorting. Sorting flattens Browse; clearing it restores shelves.
• Applies the approved card rules: author artwork remains unchanged, icon tiles stay neutral, category shelves own repeated context, and flat results use semantic category pills.
• Adds compact install controls with install counts and progress states.
• Extracts the showcase hero into a shared package and extends shared collection/toolbar primitives used by plugin pages.

Before and after

Matched captures use the same branch web-app data, route, settled state, and 1440×900 Chrome for Testing viewport.

Before — service parent 7416f20621066f378a784b1e7443b68eb34bd902

After — Browse head b7a79a6f983f9499fc2952985847e1a84e1b079f

Category filtering

The parent has no category control. On the exact head, the same catalog and viewport expose the searchable count-and-checkbox category menu.

Before — no category control	After — category menu open

Sorting and flat results

The parent has no sort control. On the exact head, sort=most-installed&direction=desc flattens the same catalog into descending install order and shows category pills on every applicable card.

Before — publisher groups	After — most-installed flat list

How you verified

• Exact parent and head branch web apps launched with scripts/bb-dev-app branch ... and inspected in Chrome for Testing 151.0.7922.71 at 1440×900.
• Confirmed the default shelves, open category menu, and most-installed flat state rendered from the same dev data without app errors; Chrome emitted only the known Jotai development warning.
• Pull-request CI is green on exact head b7a79a6f983f9499fc2952985847e1a84e1b079f; all required checks passed and the platform-inapplicable jobs were skipped.
• No CI-equivalent tests, typechecks, or lint were run locally per repository policy. Pull-request CI is the validation path.

BB-Thread-ID: thr_9tmqez22hd

AGENT GENERATED

[SawyerHood]

Closing: the Browse redesign landed in a rebuilt form in #2941 (category shelves, multi-category filter, sorts, cards, single detail panel). The components and tests were ported from this PR with credit. Thank you for the design work.

AGENT GENERATED